The present disclosure generally relates to ultrasonic treatment systems for separating compounds in an aqueous solution. More particularly, the present disclosure relates to ultrasonic treatment systems that use ultrasonic energy to provide efficient and effective removal of compounds from aqueous effluents, such as textile effluents.
In nearly all textile dyeing and printing processes, some fraction of the applied colorant will not bind to the substrate. These unbound dyes and reactants are typically removed by a water rinsing process, generating large quantities of textile effluent that must be disposed of in an environmentally acceptable manner.
Previous attempts have disposed of the textile effluent by passing the effluent through an ion exchange resin or activated carbon. During these reactions, such materials or resins adsorb the dyes and other soluble components in the textile effluent slowly and require large volumes of the adsorbent to perform effectively.
Other attempts have utilized continuous chemical reactors such as a plug flow reactor containing adsorbent beads or particles having specific surface functionalities, through which dyes and reactants found in textile effluents are adsorbed. Specifically, the beads or particles are packed into a column in the plug flow reactor and an aqueous solution of textile effluent is pumped through the column, thereby exposing the surface of the beads or particles to allow for adsorption of the dyes and reactants in the effluent to occur. These moieties can be adsorbed onto the surface and within the pores of the beads or particles.
One problem with processing textile effluent through a column such as that of a conventional plug flow reactor, is that many of the compounds to be adsorbed (e.g., dyes and reactants) must travel through a hydrodynamic boundary layer surrounding the bead or particle. This boundary layer is a source of resistance for the compounds, which prolongs the adsorption process and increases time and costs of the removal of unbound dyes and reactants from textile effluents.
One previous attempt to reduce adsorption time required to remove the compounds from textile effluents is by increasing flow rate of the processing stream in the plug flow reactor. This reduces the thickness of the hydrodynamic boundary layer, which enhances the rate at which the transport of compounds to the surface of the beads and particles can occur. This solution, however, results in less residence time in the plug flow reactor for the adsorption process to occur. Additionally, there is increased pressure drop across the reactor, and as such, larger plug flow reactor geometries and processing equipment are required.
Based on the foregoing, there is a need in the art for an ultrasonic treatment system, such as a plug flow reactor, that prevents a thick hydrodynamic boundary layer from forming, and thus, allows for quicker more efficient removal of compounds such as dyes and reactants from aqueous effluents.